Double twist spindle



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V M m z a M w m a H 6 8 C 7 7 v 3 I nnh-n--- m- Nov. 27, 1951 c. B. KINGSBURY DOUBLE TWIST SPINDLE Filed Dec. 19, 1949 tionary structure which carries the Patented Nov. 27, 1951 UNITED STATES PATENT OFFICE- 2,576,124 DOUBLE 'rwrs'r SPINDLE Chadwick B. Kingsbury,

signor to North Ameri New York, N. Y., a co Elizabethton, Tenn., ascan Rayon Corporation, rporation of Delaware Application December 19, 1949, Serial No. 133,841 7 Claims. (01. 57-58) being transmitted in amplified form to another portion and causing improper functioning of the tensioning device of the spindle and damage to the yarn.

To this end the invention contemplates providing a twisting spindle assembly wherein a stayarn package is supported by bearings in non-rotating but permissibly yratory relation on a rotating structure and wherein resilient means are interposed between said structures for preventing the transmission of oscillatory movements or vibrations from the rotating structure to the stationary structure.

Another object is to provide a twisting spindle structure wherein the vibration damping means interposed between the rotating and non-rotating structures is constituted as a sleeve or bushing made of resilient material such as rubber,

- synthetic plastic, or the like.

A further object is to provide a spindle struc-- ture that is adapted to embody such a vibration damping sleeve without requiring the machining of the spindle portion which carries the same to be carried to an uneconomical degree of accuracy.

Another object is so to arrange the means-used for preventing the transmission, to the stationary structure, of the oscillatory vibration producing movements of the rotating structure, as not to restrain such movements to an extent which may impose undue strain on the bearings.

A still further object is to provide a spindle structure of which the resilient vibration damping members are constituted as readily removable and replaceable elements adapted to facilitate inspection, assembling and dismantling of the spindle.

In twisting spindles of the double twist type, the yarn package supporting portion contains an a so-called balloon, the twisted yarn then passing through a gathering eye and thence to a takeup package. In order to control the pull exerted by the balloon on the supply package, a tensioning means is disposed in the path traveled by the yarn on its way from the supply package to In double twist spindlesthe ballooning zone. where a free balloon is formed, it is customary to provide 'such tensioning means at or near the point where the yarn drawn from the supply package enters the central bore of the spindle at the top.

Such a tensioning means may, comprise a disklike member reposing on a support surface on the top of the spindle, the disk being provided with a depending stem extending loosely into the bore of the spindle. The yarn, drawn from the supply package, passes between the bottom surface of the disk and its support surface, down past the loosely fitting stem and thence through the bore in the spindle to a passage in the storage wheel or rotor, from which it emerges through a periph eral port thereon, thereafter forming the balloon aforesaid. An embodiment of a tensioning arrangement of this type, applied to a double twist spindle is disclosed for example in the copending application of Chadwick B. Kingsbury, Serial No. 118,645, filed September 29, 1949.

It has been found however that oscillatory movements and vibrations are produced in the rotating portion of the spindle due to minute ininternal passage or bore extending from the top to the rotor or storage wheel. During operation of the spindle, yarn drawn from the yarn supply package enters the aforesaid bore at the top, passes down through the passage, enters a radial passage in the rotor and finally emerges from said passage. It then travels up, outwardly around in spaced relation to the spindle forming accuracies in machining, variations in density of .the constructional materials used,.or other causes. While such vibrations are minute and ordinarily of no consequence at their place of origin, they become amplified by lever action as a function of the length of the parts through which they are transmitted. Moreover, despite extremecare in machining and balancing the rotating portion and the use of precision bearings for mounting the same, it is practically impossible to avoid a minute amount of so-called runout or lack of coaxiality between the journaled bottom of the rotating member and the free or non-journaled top portion thereof. This minute amount of run-out causes oscillation of the top portion at the point where the non-rotating yarn package support portion is carried. These oscillations are imparted to the stationary portion of the spindle and propagated through the latter to the locality of the tensioning disk. The oscillatory movements at that point may be of sufiicient magnitude to cause the stem of the disk to oscillate radially within the confines of the bore in which it reposes in loosely fitting fashion. Since the yarn, as it passes from the supply package to the rotor, must also pass through the bore and alongside the aforesaid stem, the yarn may become pinched between the stem and the inner wall of the bore and sheared oil. or at least weakened at intervals along its length. One object of the invention therefore is to provide means for preventing the vibrations or oscillations of the rotating portion of the spindle from being transmitted to the stationary portion and propagated through the latter to the tensioning device. Such means is constituted as a resilient damping device constituted as a resilient sleeve interposed between the rotating and stationary parts of the spindle.

Furthermore, although it is theoretically possible in the-case of such spindles to provide bearings rigid enough to prevent the production of vibrations or oscillations in the spindle and to use expedients for balancing the spindle, such procedures are very costly. Moreover, .if the oscillations or vibrations are completely restricted by rigid bearing structures, an undue degree of strain and wear is placed on the entire spindle assembly. The resilient damping means provided by the present invention, in addition to preventing the transmission of vibrations to the tensioning device also allows the spindle structure to vibrate or oscillate to a limited degree without imposing undue strain on the bearings.

Spindles of this type are used in large quantities and it is obvious that if the manufacturing tolerances required in their production are extended to extreme limits their cost would become prohibitive. It has been found desirable therefore to machine the parts of the metallic rotating structure as accurately as is economically possible and to fabricate the stationary portion, that cooperates therewith, from synthetic resins or the like, as by molding.

However it is difficult to hold molded parts to extreme tolerance and equally diiiicult to mold live resilient materials such as rubber to similar tolerances. For this reason, whenever rubber vibration absorbing members have been used in spindle structures they have heretofore been applied generally in the form of pre-loaded or otherwise stressed structures usually bonded integrally to certain of the parts of the spindle or held in, compressive relation between such parts.

In accordance with the present invention however, the stationary portion of the spindle that receives the resilient vibration-damping sleeve is so constructed as to permit facile insertion and removal of the sleeve while also precluding the necessity for close manufacturing tolerances in both the sleeve and the stationary portion of the spindle that carries it. The resilient member is therefore not integrally retained in vulcanized or otherwise bonded form to any portion of the spindle.

An embodiment of the invention is. shown in the the acompanying drawing, where:

Fig. 1 is a side elevation partly in section of a double twist spindle provided with one suitable form of vibration damping means.

- Fig. 2 is a cross section taken on line 22 of Fig. 1 through the central lower portion of the spindle and the vibration absorbing sleeve.

Fig. 3 is a longitudinal section corresponding to Fig. 2 showing the internal construction of the portion in which the vibration absorbing sleeve is housed.

Fig. 4 shows the resilient sleeve per se.

Referring in detail to the drawing, the invention is illustrated as applied to a double twist spindle representative of those used in the art, although the invention is not limited in its application to thisparticular type. In the illustrative embodiment chosen the spindle comprises a rotating portion and a non-rotating structure carried by said rotating portion, said non-rotating structure being however permitted to gyrate to and fro on the'rotating structure.

The rotating portion includes the whorl I mounted on bearings therein (not shown) and attached as by the nut 8 on its support shaft to an arm 2 pivoted at 3 to a bracket 4 of the spindle bank of a machine. The drive system for operating the spindle includes the belt 5, idler pulley 8 mounted on rail 1 and a brake indicated by 2 and operated by handle III. II is a stationary 'portion of the bearing system carried by the arm 2.

Associated for rotation with the whorl I is the socalled rotor or storage wheel l2 characteristic of this type of double twist spindle. This is provided with radial ports I3 through which the yarn issues after passing downwardly through the "central bore of the spindle and it is from the rotor l2 that the so-called balloon of yarn proceeds upwardly and whirls in spaced relation around the spindle. The non-rotating portion of the spindle comprises a structure carried by the rotating portion through intermediary of suitable bearings. In the embodiment shown, these bearings are indicated by M and I5. This non-rotating portion of the spindle is constituted so as to serve as a support for the yarn that is to be twisted. To this end it is formed as a bowlshaped structure I6 which carries the spool or sleeve I! that holds the yarn or thread It. The bowl-shaped structure carries a central, upwardly extending member l9 having screw threads at its upper portion upon which is screwed an upwardly extending tubular extension 20 having a flange 2| for centering the conical cap 22 of the spindle. The flange 23 of the cap 22 rests on the sleeve ll of the yarn package l8 and an internal downwardly extending portion 24 is carried by the tubular extension 20.

The yam, drawn from package It, passes in the direction of arrow 25 to the top of the spindle and between the cooperating parts of the tensioning device. This comprises the support 26, carried by cap 22, and the disk 21 with its stem 28. The support member 26 has a central bore and successive coaxial and contiguously located bores 29, 30 in the center of the spindle lead to the radial passage l3 of the rotor or storage wheel l2. The yarn passes downwardly through the spindle and, upon emerging, forms the balloon, represented as if in stroboscopically stopped position, by the line 3|.

The inside structure of the spindle also includes an inverted cup-like member 32 and a biasing weight 32 carried by an arm 14 retained by the central portion of the bowl-like structure. This weight serves to keep the stationary portion of the spindle in a fixed position relatively to the rotating portion represented by the whorl I. The stationary portion, represented generally by the bowl l6, yarn package, cap 22 and parts 20, 24, and 32 is able to gyrate or perform partial rotations with respect to the rotating portion as a result of undue pull or drag exerted on the yarn leaving the package It and is brought back to its position of rest by the weight 32. The various parts such as the bowl-like memher I! and cap 22 are preferably made of a suitable molded synthetic material or plastic.

, In order to prevent the oscillatorymovements of the rotating portion from being imparted to the stationary portion and propagated through the structure oi the latter to the tensioning' device, a resilient vibration damping means is interposed between the two portions. In the preferred embodiment of the invention this is constituted as a sleeve as shown separately in Fig. 4. This is preferably made of live rubber,

although a suitable resilient plastic material may be used. The sleeve has a tubular upper portion 35 with an internally extending flange 38. The bottom of the sleeve hasan outwardly extending portion 31 in the general form of a large chamfered flange. This sleeve is shown in crossand a similar recess in the large lower chamfered flange accommodates the bearing ii. In each case however no preloading stress is imposed on the sleeve or any substantial compressional stress when the sleeve is in place. De-

pending on the construction of the spindle and the size of the bearings used, the proportions of the sleeve and the size oi the recesses may vary accordingly.

The sleeve is retained inplace in the spindle as shown in Fig. 1. It flts snugly but without pre loading stress into the bore of the internally upwardly extending portion is of the bowl-like member IS. The inside wall of this bore is provided with small ribs 38 as shown partly in Fig. 1 and in greater detail in Figs. 2 and 3. These ribs take up any irregularities present between the rubber sleeve and the walls of the bore of the member IQ-without unduly compressing the rubber. The resilient sleeve can therefore be easily inserted and retained without deforming the entire mass of the rubber inasmuch as only the small ribs dig into the rubber. The ribs extend vertically in spaced relationabout the inside wall of the member I! and outwardly from said wall to the extent of approximately twenty thousandths of an inch. In the preferred embodiment -,they extend vertically slightly more than half way down the bore and said bore may be slightly relieved beyond that point and tapered if desired, to facilitate fitting of the sleeve. The headings may of course also extend completely down the wall of the bore. As shown in Fig. 4 the tubular portion -01 the sleeve may be slightly tapered to facilitate fitting into the bore.

In assembling the spindle the resilient sleeve is arranged to embrace the bearings I land II on the rotating portion of the spindle which carry the non-driven or so-called stationary part. The internally beaded portion I9 of the bowl-like structure is is then forced over the tubular portion of the sleeve so as to occupy the position shown in section in Fig. 1.

Due to the presence of the sleeve, any oscillation of the rotating portion of the spindle is effectively damped and is prevented from reaching the stationary structure and from being propagated therethrough in amplified form. The upstanding portion is of the bowl-like structure is externally threaded as at 38 to receive the tubular central portion 20 of the spindle which in turn aids in supporting the cap or top 22. The

spindle portion having a bore bore, the longitudinally spaced headings for engaging said aware;

, 8 result is that the non-rotating portion of the spindle is'constituted as a unitwhich is carried in vibration-insul ted fashion by the rotating portion.

Due to the hereinbefore described method of applying the resilient sleeve and the beaded structureiof the spindle portion into' which it fits, the sleeve may be readily removed during the dismantling of the spindle to permit inspection of the bearings. The sleeves as well as the bore that receives it need not be finished to uneconomical size tolerances and may be manufactured in quantities for use on any spindle of a given type.

While this invention has been described in detail with respect to certain preferred embodiments it is, of course, understood that various modifications may be made therein and it is therefore not desired to limit theinvention to the exact details described and shown except in so far as they are defined by the claims.

What is claimed is: v

1. In a double twist spindle the combination of a stationary shaft, a driven spindle portion and a non-driven spindle portion, one end of said driven portion being arranged for rotation'on said shaft, the other end of said driven portion carrying bearings for supporting said non-driven spindle portion for permissible partially rotational gyration on said bearings relatively to said driven portion, a bore in said non-driven portion, a resilient sleeve embracing said bearings, said sleeve said bearings being carried in said all of said bore being provided with sleeve to retain said sleeve condition of repose.

. 2. In a double twist spindle of the type comprising a driven portion and a stationary portion in a non-preloaded mounted on bearings on said driven portion forpermissible gyratory movement relatively therewith and wherein yarn is drawn from a package carried by said stationary portion, passes through a tensioning device carried by said stationary portion and then through the driven por-- tion and issues from the latter, thereafter forming a balloon, the improvement which comprises the provision of a bore in a portion of said nondriven portion, a rubber sleeve disposed between said driven portion and said stationary portion and embracing said bearings whereby to prevent the transmission of vibrations from said driven portion to said stationary portion and their propagation in amplified form through said stationary portion to said tensioning device, the inner wall of said bore having longitudinal headings for engaging said sleeve in non-preloaded condition with a minimum of compressional strain.

3. In a double twist spindle wherein a driven portion carries a non-driven portion, the improvement comprising the provision or sets of bearings in spaced relation on said driven portion for carrying said non-driven portion, a single resilient sleeve having internal recesses for embracing said bearings, a bore in said nondriven portion for receiving said sleeve and iongitudinal ribs extending radially outward from the inside wall of said bore for engaging said resilient sleeve at spaced substantially line-contact portions whereby to retain said sleeve in a condition of non-preloaded repose substantially de-,. void of compressional strain.

4. In a double twist spindle the combination of a stationary shaft. a driven spindle portion, a non-driven spindle portion, said non-driven for receiving the top of said driven spindle portion, upper and lower sets of bearings carried in spaced relation by said driven spindle portion in said bore, and a sleeve of resilient material fitted into said bore substantially throughout the length thereof, the outside surface of said sleeve fitting snugly against the inside surface of said bore, said sleeve having recesses in the end portions thereof for receiving and for encircling said upper and lower sets of bearings, the portion of said sleeve extending between said sets of bearings being spaced from said driven spindle portion.

5. In a double twist spindle the combination of a stationary shaft, a driven spindle portion, a non-driven spindle portion, said non-driven spinto facilitate fitting into said bore and sums snugly into said bore without preloading stress.

dle portion having-a bore for receiving the top of said driven spindle portion, upper and lower sets of bearings carried in spaced relation by said driven spindle portion in said bore, and a live rubber sleeve fitted into said bore substantiall throughout the length thereof for encircling said upper and lower sets of bearings, said rubber sleeve being slightly tapered to facilitate fitting into said'bore and fitting snugly into said bore without preloading stress.

6. In a double twist spindle the combination of a stationary shaft, a driven spindle portion, a non-driven spindle portion, said non-driven spindle portion having a bore for receiving the top of said driven spindle portion, upper and lower sets of bearings carried in spaced relation by said driven spindle portion in said bore, and a sleeve of resilient material fitted into said bore substantially throughout the length thereof, said sleeve having recesses in the end portions thereof for receiving and for encircling said upper and lower sets of bearings, said sleeve being slightly tapered 7. In a double twist spindle the combination of a stationary shaft, a driven spindle portion, a non-driven spindle portion, said non-driven spindle portion having a bore for receiving the top of said driven spindle portion, upper and lower sets of bearings carried in spaced relation by said driven spindle portion in said bore, and a sleeve of resilient material fitted into said bore substantially throughout the length thereof, said sleeve having recesses in the end portions thereof for receiving and for encircling said upper and lower sets of bearings. the bottom portion of said sleeve being of substantially larger diameter than the upper portion thereof to provide substantially greater thickness of said resilient sleeve between said lower set of bearings and the corresponding inner surface of said bore than is provided around said upper set of bearings, the outside portion of said sleeve extending between-said sets of bearings being slightly tapered to facilitate fitting into said bore and fitting snugly into said bore without preloading stress.

CHADWICK B. KINGSBURY.

REFERENCES CITED The following references are of record in the Kent July 3, 1945 

